This essay, to be published in Civil Rights Stories (Myriam Gilles & Risa Goluboff, eds., forthcoming 2007), tells the story of US Airways v. Barnett. Barnett, which involved an employee's request that his employer modify its seniority system as a disability accommodation, the Supreme Court confronted for the first time the Americans with Disabilities Act's requirement of reasonable accommodation in employment. Barnett ultimately offers a window into three of the most important issues to understand about the ADA's accommodation requirement: the requirement's relationship to more traditional antidiscrimination mandates; its seemingly zero-sum nature; and the limits of its usefulness in a world of reduced job security for everyone.